Estrogen Protects against Renal Ischemia-Reperfusion Injury by Regulating Th17/Treg Cell Immune Balance

The role of sex and gender in acute kidney injury-consensus statements from the 33rd Acute Disease Quality Initiative

Sex differences exist in acute kidney injury (AKI), and the role that sex and gender play along the AKI care continuum remains unclear. The 33rd Acute Disease Quality Initiative meeting evaluated available data on the role of sex and gender in AKI and identified knowledge gaps. Data from experimental models, pathophysiology, epidemiology, clinical care, gender, social determinants of health, education, and advocacy were reviewed. Recommendations include incorporating sex and gender into research along the bench-to-bedside spectrum; analyzing sex-stratified results; evaluating the effects of sex chromosomes, hormones, and gender on outcomes; considering fluctuations of hormone levels; studying the impact gender may have on access to care; and developing educational tools to inform patients, providers, and stakeholders. This meeting report summarizes what is known about sex and gender along the AKI care continuum and proposes an agenda for translational discovery to elucidate the role of sex and gender in AKI across the lifespan.

FPR1 affects acute rejection in kidney transplantation by regulating iron metabolism in neutrophils

BACKGROUND

Acute rejection (AR) is one of the significant factors contributing to poor prognosis in patients following kidney transplantation. Neutrophils are the main cause of early host-induced tissue injury. This paper intends to investigate the possible mechanisms of neutrophil involvement in acute rejection in renal transplantation.

METHODS

Samples were analyzed for their relationship with immune cells using CIBERSORT. WGCNA was used to identify modules with high relevance to neutrophils and hub genes in the modules were extracted. The effect on neutrophil function after blocking formyl peptide receptor 1 (FPR1) was tested in vitro experiments. The effects of blocking FPR1 on neutrophil function as well as acute rejection were tested in vivo after constructing a mouse kidney transplant model.

RESULTS

The proportion of neutrophils was higher in the AR group than in the non-rejection group, and FPR1 was identified as an important gene in the regulation of acute rejection in kidney transplantation by neutrophils. At the cellular level, blocking FPR1 inhibited the activation of the ERK1/2 pathway, decreased ferrous ion content, affected the expression of iron metabolism-related proteins, and suppressed the formation of NETs. In the acute rejection model of renal transplantation, blockade of FPR1 decreased graft neutrophil infiltration and NETs content. Meanwhile, blocking FPR1 attenuated graft injury during acute rejection.

CONCLUSION

This study found that FPR1 might be an important molecule involved in neutrophils during acute rejection of kidney transplantation, explored the relationship between kidney transplantation and neutrophils, and provided potential treatment methods for clinical practice.

Yishen Jiangzhuo decoction attenuates cisplatin‑induced acute kidney injury by inhibiting inflammation, oxidative stress and apoptosis through the TNF signal pathway

The present study aimed to investigate the therapeutic effects and mechanisms of Yishen Jiangzhuo decoction (YSJZD) in a mouse model of cisplatin-induced acute kidney injury (AKI). The mice were divided into the NC, cisplatin and cisplatin + YSJZD groups. A concentration-dependent effect of YSJZD on cisplatin-induced AKI was observed and the optimal concentration for intervention was calculated. Changes in blood urea nitrogen and serum creatinine levels combined with hematoxylin and eosin and periodic acid-Schiff staining and transmission electron microscopy observations indicated that YSJZD enhanced renal function, reduced pathological injury and protected renal tubular epithelial cells in cisplatin-induced AKI mice. The results of the transcriptomic and enrichment analyses showed that the mechanisms of YSJZD may be associated with inflammation, oxidation, apoptosis and the TNF signal pathway. Immunofluorescence, oxidative stress index, terminal deoxynucleotidyl transferase dUTP nick end labeling assay and western blotting revealed that YSJZD downregulated apoptosis in the renal tissues of AKI mice and further decreased the expression levels of p-p65, p-p38 MAPK, TNF-α, cleaved-caspase-3 and malondialdehyde, while increasing the levels of NAD-dependent protein deacetylase sirtuin-3, glutathione and superoxide dismutase. Overall, the results showed that YSJZD could effectively abrogate cisplatin-induced AKI in mice through mechanisms primarily related to its anti-inflammatory, antioxidative and antiapoptotic effects by inhibited the TNF signal pathway. YSJZD warrants further investigation as a clinical empirical prescription.

Sex differences in the association of long-term exposure to heat stress on kidney function in a large Taiwanese population study

The incidence and prevalence of dialysis in Taiwan are high compared to other regions. Consequently, mitigating chronic kidney disease (CKD) and the worsening of kidney function have emerged as critical healthcare priorities in Taiwan. Heat stress is known to be a significant risk factor for CKD and kidney function impairment. However, differences in the impact of heat stress between males and females remains unexplored. We conducted this retrospective cross-sectional analysis using data from the Taiwan Biobank (TWB), incorporating records of the wet bulb globe temperature (WBGT) during midday (11 AM-2 PM) and working hours (8 AM-5 PM) periods based on the participants' residential address. Average 1-, 3-, and 5-year WBGT values prior to the survey year were calculated and analyzed using a geospatial artificial intelligence-based ensemble mixed spatial model, covering the period from 2010 to 2020. A total of 114,483 participants from the TWB were included in this study, of whom 35.9% were male and 1053 had impaired kidney function (defined as estimated glomerular filtration rate < 60 ml/min/1.73 m2). Multivariable analysis revealed that in the male participants, during the midday period, the 1-, 3-, and 5-year average WBGT values per 1 ℃ increase were significantly positively associated with eGFR < 60 ml/min/1.73 m2 (odds ratio [OR], 1.096, 95% confidence interval [CI] = 1.002-1.199, p = 0.044 for 1 year; OR, 1.093, 95% CI = 1.000-1.196, p = 0.005 for 3 years; OR, 1.094, 95% CI = 1.002-1.195, p = 0.045 for 5 years). However, significant associations were not found for the working hours period. In the female participants, during the midday period, the 1-, 3-, and 5-year average WBGT values per 1 ℃ increase were significantly negatively associated with eGFR < 60 ml/min/1.73 m2 (OR, 0.872, 95% CI = 0.778-0.976, p = 0.018 for 1 year; OR, 0.874, 95% CI = 0.780-0.978, p = 0.019 for 3 years; OR, 0.875, 95% CI = 0.784-0.977, p = 0.018 for 5 years). In addition, during the working hours period, the 1-, 3-, and 5-year average WBGT values per 1 ℃ increase were also significantly negatively associated with eGFR < 60 ml/min/1.73 m2 (OR, 0.856, 95% CI = 0.774-0.946, p = 0.002 for 1 year; OR, 0.856, 95% CI = 0.774-0.948, p = 0.003 for 3 years; OR, 0.853, 95% CI = 0.772-0.943, p = 0.002 for 5 years). In conclusion, our results revealed that increased WBGT was associated with impaired kidney function in males, whereas increased WBGT was associated with a protective effect against impaired kidney function in females. Further studies are needed to elucidate the exact mechanisms underlying these sex-specific differences.

The combinatorial effect of age and biological sex on alloimmunity and transplantation outcome

Both age and biological sex affect transplantation outcomes. We have recently shown in a large volume clinical analysis utilizing the SRTR data that graft survival is inferior in young female kidney transplant recipients. In this multi-factorial analysis, older female recipients presented with a trend towards improved transplant outcomes compared to both young female recipients and male recipients of any age. Those data supported by reports of those of others suggest that sex and age impact alloimmune responses both, individually and synergistically. Biological sex and hormone levels change throughout a lifetime with recognized effects on longevity in addition to an impact on the development and course of several disease preconditions. Detailed mechanisms of those sex and age-specific aspects have thus far been studied outside of transplantation. Effects on alloimmunity are largely unknown. Moreover, the combinatorial impact that both, biological sex and age have on transplant outcomes is not understood. Here, we summarize available data that analyze how age in combination with biological sex may shape alloimmune responses and affect transplant outcomes.

Severe epididymal orchitis and total testicular infarction induced by Pseudomonas aeruginosa infection, and assessment of testicular endocrine function: A case report

Epididymal orchitis is a common urological condition for which medical management is the primary treatment strategy. Although Pseudomonas aeruginosa is a common cause of nosocomial urinary tract infections, it rarely causes acute epididymal orchitis in adolescence and is difficult to treat. Furthermore, it may progress to potentially fatal complications such as global testicular infarction and late atrophy. Urinary tract infection(s) can harm the gonads and is a well-known cause of male infertility. This case study involved a 13-year-old boy with acute epididymal orchitis caused by P. aeruginosa infection, which led to testicular infarction. Testicular volume, and anti-sperm antibody, reproductive hormone, and serum inhibin B levels were monitored for six months, which revealed that left testicular volume was 1/20 of that of the right. Anti-sperm antibodies were negative, oestradiol level was elevated, but serum inhibin B level declined. This case report emphasises the importance of early treatment by implementing the use of antibiotic(s) to maximise the opportunity for testicular rescue. Testicular function on the healthy side must be monitored when testicular necrosis is detected.

Asiaticoside ameliorates renal ischemia/reperfusion injury by promoting CD4+CD25+FOXP3+ treg cell differentiation

Ischemia/reperfusion injury (I/R) is the major cause of acute kidney injury, which becomes a global health problem. The effects of asiaticoside, as an anti-inflammatory drug, on renal ischemia-reperfusion injury have not been well defined. After the CD4+ cells were treated with asiaticoside, the CD4+CD25+FOXP3+ Treg cell differentiation was detected by flow cytometry. The viability and release of inflammatory factors of CD4+CD25+FOXP3+ Treg cell were detected by CCK-8 and ELISA. Renal I/R injury mice model was established, and the mice were pre-treated with asiaticoside or CD25 antibody or infused with Treg cells. The histological changes of renal tissue were evaluated by Hematoxylin-eosin, PAS, and Masson staining. The renal function markers were evaluated by colorimetry, the release of inflammatory factors was determined by ELISA. The Th17 and Treg cells in the blood and spleen were quantified by flow cytometry. The expressions of FOXP3 and RoR-γt in renal tissues were determined by western blotting. Asiaticoside promoted CD4+CD25+FOXP3+ Treg cell differentiation, increased the cell viability and down-regulated TNF-α, IL-1β, and IL-6, while up-regulated IL-10 of CD4+CD25+FOXP3+ Treg cells. Moreover, asiaticoside ameliorated the histological damage, decreased the Th17 cells and increased Treg cells, and down-regulated the TNF-α, IL-1β, IL-6, blood urea nitrogen, serum creatinine, and RoR-γt, while up-regulated IL-10 and FOXP3 of renal I/R injury mice. Effect of asiaticoside on renal I/R injury mice was reversed by CD25 antibody whose role was further reversed by Treg cell infusing. In conclusion, asiaticoside ameliorated renal I/R injury due to promoting CD4+CD25+FOXP3+ Treg cell differentiation.

Gal-9/Tim-3 signaling pathway activation suppresses the generation of Th17 cells and promotes the induction of Foxp3+ regulatory T cells in renal ischemia-reperfusion injury

CD4⁺ T cells mediate the pathogenesis of renal ischemia-reperfusion injury (IRI). Emerging research suggests that a Th17/regulatory T cell (Treg) imbalance plays a pivotal role in the development of renal IRI. A recently identified negative checkpoint protein, T cell immunoglobulin domain and mucin domain family 3 (Tim-3), inhibits the immune response by binding to its ligand, galectin-9 (Gal-9). However, the role of the Gal-9/Tim-3 signaling pathway in the regulation of CD4⁺ T cell subsets in renal IRI remains unclear. In this study, we investigated the effect of the Gal-9/Tim-3 signaling pathway on Th17/Treg subsets in renal IRI using a mouse model. Renal IRI induced the expression of Gal-9 in renal tubular epithelial cells and increased the proportion of Tim-3⁺ Th17 cells and Tim-3⁺ forkhead box P3 (Foxp3)⁺ Treg cells in the ischemia-reperfusion (IR) kidneys. Administration of rAAV9-Gal-9 suppressed kidney inflammation, reduced the mortality of mice with renal IRI, increased Foxp3⁺ Treg cells, and reduced Th17 cells. In contrast, the blockade of Tim-3 in vivo using an anti-Tim-3 monoclonal antibody aggravated renal inflammation, decreased Foxp3⁺ Treg cells, and promoted Th17 cells. Thus, Gal-9/Tim-3 signaling pathway activation may protect against renal IRI by inhibiting Th17 cell production and inducing Foxp3⁺ Treg cell expansion. Our study suggests that the Gal-9/Tim-3 signaling pathway may be targeted by immunotherapy in renal IRI.